Method and apparatus for charged particle detection

    公开(公告)号:US11295930B2

    公开(公告)日:2022-04-05

    申请号:US16484106

    申请日:2018-02-01

    Abstract: Systems and methods are provided for charged particle detection. The detection system can comprise a signal processing circuit configured to generate a set of intensity gradients based on electron intensity data received from a plurality of electron sensing elements. The detection system can further comprise a beam spot processing module configured to determine, based on the set of intensity gradients, at least one boundary of a beam spot; and determine, based on the at least one boundary, that a first set of electron sensing elements of the plurality of electron sensing elements is within the beam spot. The beam spot processing module can further be configured to determine an intensity value of the beam spot based on the electron intensity data received from the first set of electron sensing elements and also generate an image of a wafer based on the intensity value.

    Apparatus of plural charged-particle beams

    公开(公告)号:US10811222B2

    公开(公告)日:2020-10-20

    申请号:US16200421

    申请日:2018-11-26

    Abstract: A secondary projection imaging system in a multi-beam apparatus is proposed, which makes the secondary electron detection with high collection efficiency and low cross-talk. The system employs one zoom lens, one projection lens and one anti-scanning deflection unit. The zoom lens and the projection lens respectively perform the zoom function and the anti-rotating function to remain the total imaging magnification and the total image rotation with respect to the landing energies and/or the currents of the plural primary beamlets. The anti-scanning deflection unit performs the anti-scanning function to eliminate the dynamic image displacement due to the deflection scanning of the plural primary beamlets.

    APPARATUS OF PLURAL CHARGED-PARTICLE BEAMS
    33.
    发明申请

    公开(公告)号:US20200152421A1

    公开(公告)日:2020-05-14

    申请号:US16734219

    申请日:2020-01-03

    Abstract: A multi-beam apparatus for observing a sample with high resolution and high throughput and in flexibly varying observing conditions is proposed. The apparatus uses a movable collimating lens to flexibly vary the currents of the plural probe spots without influencing the intervals thereof, a new source-conversion unit to form the plural images of the single electron source and compensate off-axis aberrations of the plural probe spots with respect to observing conditions, and a pre-beamlet-forming means to reduce the strong Coulomb effect due to the primary-electron beam.

    Apparatus of plural charged-particle beams

    公开(公告)号:US10573487B2

    公开(公告)日:2020-02-25

    申请号:US16174146

    申请日:2018-10-29

    Abstract: One modified source-conversion unit and one method to reduce the Coulomb Effect in a multi-beam apparatus are proposed. In the modified source-conversion unit, the aberration-compensation function is carried out after the image-forming function has changed each beamlet to be on-axis locally, and therefore avoids undesired aberrations due to the beamlet tilting/shifting. A Coulomb-effect-reduction means with plural Coulomb-effect-reduction openings is placed close to the single electron source of the apparatus and therefore the electrons not in use can be cut off as early as possible.

    Apparatus of plural charged-particle beams

    公开(公告)号:US10541110B2

    公开(公告)日:2020-01-21

    申请号:US15925606

    申请日:2018-03-19

    Abstract: A multi-beam apparatus for observing a sample with high resolution and high throughput and in flexibly varying observing conditions is proposed. The apparatus uses a movable collimating lens to flexibly vary the currents of the plural probe spots without influencing the intervals thereof, a new source-conversion unit to form the plural images of the single electron source and compensate off-axis aberrations of the plural probe spots with respect to observing conditions, and a pre-beamlet-forming means to reduce the strong Coulomb effect due to the primary-electron beam.

    Charged particle beam apparatus with multiple detectors and methods for imaging

    公开(公告)号:US12142455B2

    公开(公告)日:2024-11-12

    申请号:US17226017

    申请日:2021-04-08

    Abstract: Systems and methods of imaging a sample using a charged-particle beam apparatus are disclosed. The charged-particle beam apparatus may include a compound objective lens comprising a magnetic lens and an electrostatic lens, the magnetic lens comprising a cavity, and an electron detector located immediately upstream from a polepiece of the magnetic lens and inside the cavity of the magnetic lens. In some embodiments, deflectors may be located between the electron detector and the opening of the polepiece adjacent to the sample to achieve a large field of view. Electron distributions among the detectors can be manipulated without changing the landing energy by changing the potential of the control electrode(s) in the electrostatic objective lens. The electron source can be operated with several discrete potentials to cover different landing energies, while the potential difference between electron source and the extractor is fixed.

    Multi-beam inspection apparatus
    37.
    发明授权

    公开(公告)号:US12142453B2

    公开(公告)日:2024-11-12

    申请号:US17583176

    申请日:2022-01-24

    Abstract: A multi-beam inspection apparatus including an improved source conversion unit is disclosed. The improved source conversion unit may comprise a micro-structure deflector array including a plurality of multipole structures. The micro-deflector deflector array may comprise a first multipole structure having a first radial shift from a central axis of the array and a second multipole structure having a second radial shift from the central axis of the array. The first radial shift is larger than the second radial shift, and the first multipole structure comprises a greater number of pole electrodes than the second multipole structure to reduce deflection aberrations when the plurality of multipole structures deflects a plurality of charged particle beams.

    Apparatus for multiple charged-particle beams

    公开(公告)号:US12080515B2

    公开(公告)日:2024-09-03

    申请号:US17718225

    申请日:2022-04-11

    Abstract: Systems and methods for observing a sample in a multi-beam apparatus are disclosed. A charged particle optical system may include a deflector configured to form a virtual image of a charged particle source and a transfer lens configured to form a real image of the charged particle source on an image plane. The image plane may be formed at least near a beam separator that is configured to separate primary charged particles generated by the source and secondary charged particles generated by interaction of the primary charged particles with a sample. The image plane may be formed at a deflection plane of the beam separator. The multi-beam apparatus may include a charged-particle dispersion compensator to compensate dispersion of the beam separator. The image plane may be formed closer to the transfer lens than the beam separator, between the transfer lens and the charged-particle dispersion compensator.

    Multiple charged-particle beam apparatus with low crosstalk

    公开(公告)号:US12033830B2

    公开(公告)日:2024-07-09

    申请号:US17944157

    申请日:2022-09-13

    Abstract: Systems and methods of enhancing imaging resolution by reducing crosstalk between detection elements of a secondary charged-particle detector in a multi-beam apparatus are disclosed. The multi-beam apparatus may comprise an electro-optical system for projecting a plurality of secondary charged-particle beams from a sample onto a charged-particle detector. The electro-optical system may include a first pre-limit aperture plate comprising a first aperture configured to block peripheral charged-particles of the plurality of secondary charged-particle beams, and a beam-limit aperture array comprising a second aperture configured to trim the plurality of secondary charged-particle beams. The charged-particle detector may include a plurality of detection elements, wherein a detection element of the plurality of detection elements is associated with a corresponding trimmed beam of the plurality of secondary charged-particle beams.

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